Force transmitting measuring mechanism



Sept. 25, 1945. P. A. STURTEVANT 2,385,

FORCE TRANSMITTING MEASURING MECHANISM Filed July 17, 1944 :s 'Sheet-Sheet 1 S INVEN TOR.

Patented Sept. 25, 1945 UNITED STATES PAT NT OFFICE FORCE TRANSMITTING MEASURING MECHANISM Paul A. Sturtevant, Elmhurst, 111.

Application July 17, 1944, Serial N0."545,333

26 Claims. (Cl. 73-139) This invention relates to force transmitting mechanism and more particularly to a mechanism of this type employing a force applying member.

When applied to mechanism of this type, the

invention broadly has to do with a force limiting structure employing two relatively movable parts and a normally rigid connection between the two parts for transmitting the force applied, there being means to release the connection and to utilize this force to create a hammer blow against the structure in order to indicate the application of a predetermined force at the work.

In this connection, the invention has for its object the creation of a hammer blow substantially equal to the force being imparted whereby a definite signal is produced by this hammer blow and the parts are automatically resettable for subsequent operation when the force ,being applied is released.

While the invention has application broadly to I a force transmitting mechanism for limiting the force being applied, it is uniquely adaptable to a structure of the type for measuring .torque employing a torque measuring device operatively disposed relative to a work-engaging member and to the handle is grasped and rotated in an arc in either direction, the force applied at the handle is transmitted to the work. As the resistance of the work causes the spring to flex, the head mem her and the handle rotate relative to the workengaging member. The force applied at the ham dle continues to move the head and handle in an arc with the work-engaging member as a pivot as the work is tightened. This rotary or pivotal movement between the head member and the work-engaging member may be measured at a dial by a pointer. The reading of the dial correctly represents, in the construction of the wrench disclosed herein, the force or torque applied by the work-engagin member to the work.

In practice, the purpose of a torque measuring wrench to apply a predetermined torqueto nuts, bolts, studs or the like and to secure thereby uniform tightening has often failed due to the carelessness of the operator and to theuse of the wrench in locations making the reading of its dial difficult. In anelfort to overcome these difficulties, provisions have been made to warn the operator by visible and audible signals upon the application of a predetermined torque at the workengaging memben Aside from giving a signal, prior art suggestions of this kind have been ineffectiveto accomplish the result intended due to the fact that the structures used permitted the attendant to disregard the signal and continue to apply a force at the handle member. These structures usually required electrical energization so that electric -cords running to the wrench were necessary. The running ofelectric cordsto a torque wrench has always been ob-jectionable'because these cards limit the maneuverability of the 'wrench in close spaces and quickly wear, the result being that the cords were soon disconnected and discarded. On the other hand, the character f'of the structure resulted in a'weak and inefiective signal, which, if audible could not be readily heard in a factory, and, if visible, could not always'be seen when the wrench would be used. Power operated devices, as distinguished-from manually ope'rabledevices, have suggested the employment of means to disconnect the'driving power from the work-engaging member when a'predetermined torque is applied and to rely upon a vibration or clicking of the parts to indicate to the operator that the power is disconnected. The arrangement of the parts did not effectively accomplish the result desired because the'continue'd operation of the power unit would detract from the clicking which was remotely disposed from the handle and would permit the operator to keep the device 'nosed against the work and apply excessive rorce to overcome the disconnection. Under no circumstances was this arrangement'adaptable to a torque transmitting device employing ahandle because the application of power was beyond and not through the handle, the latter merely being used to guide thedevice in its use,

An object of the invention is to provide, therefore, in a torque measuring wrench or in any force transmitting mechanism, a new and novel means preferably forming a part of a connection transmitting the force to the work engagin member and including a releasable part adapted to impart a hammer blow to indicate the application of a predetermined torque at the work-engaging member, 1

A further object of the invention is to provide in a device of the type described an improved form of connection between what may be termed the handle and the head member whereby a normally rigid connection is provided to transmit the force applied at the handle by the operator until a predetermined torque is applied at the workengaging member whereupon the connection is momentarily broken and the force is utilized to create a hammer blow capable of being equal to the force being applied to the handle.

A still further object of the invention is to provide a structure of the foregoing type adapted effectively to indicate by a hammer blow that a predetermined torque has been applied to the workengaging member. The operator cannot disregard, therefore, the setting of the wrench and will not carelessly continue applying force at'the handle in excess of the setting on the wrench. Moreover, the wrench may be used in any position or location and a reading of the dial or gauge will not be necessary in order to determine the force applied. A structure embodying the invention effectively jars the operator at the handle by the hammer blow and avoids continuing the application of force through the handle.

A still further object of the invention is to provide a structure of the foregoing type employing a novel form of connection between the handle member and the head member,.this connection including preferably a part normally held against relative movement with thehead member to form a rigid connection therewith but releasable by a trigger device requiring for operation but a neg ligible part of the force imparted to the handle whereby the rigid connection may be momentarily broken and the part caused to move relative to the head member and impart a hammer blow equal to the force applied to the handle.

The invention in its more specific aspects may include a trigger device operable by the indicating means registering the torque applied at the workengaging member, which trigger device is adapted normally to maintain a rigid connection at the head member to transmit the force applied atthe handle, but, when actuated by the indicating means, to break the rigid connection so that the force applied at the handle by the operator is then utilized to create a hammer blow against the handle. The trigger device is designed to require little force to operate the same and to be quickly 'resettable automatically so as to restore the rigid connection when the force is released from the handle.

A further novel feature of this invention is that any wearing of the parts of the connection, including the releasable member, will not afiect the operation of the torque wrench. The flexing of the spring bar and the action of the indicating mechanism to indicate the extent of such flexing are independent in their operation of any frictional influence resulting from such wearing of the parts. Moreover, the time of the trip releasing the connection will not be afiected by such friction inasmuch as the trip finger is set in relation to the visual reading at the dial.

Other objects and advantages of theinvention will be apparent from the following description when taken in connection with the accompanyin drawings which form a part hereof.

In the drawings:

Figure 1 is a top elevational view of a torque measuring wrench embodying the invention;

Fig. 2 is a side view of the wrench with a portion of the handle broken away;

Fig. 3 is a transverse View of the trigger device taken along line 3-3 of Fig. 4

Fig. 4 is an enlarged vertical section of that portion of the wrench which embodies the structure 'of the invention disclosed;

Fig. 5 is a similar but horizontal section of the same structure, the releasable part being shown in a non-movable position with the head member and forming a part of the rigid connection transmitting the force applied at the handle member;

Fig. 6 is the same sectional View but showing the releasable part tripped and striking the handle member to produce a hammer blow thereat;

Fig. '7 is a view similar to Fig. 5, but illustrating a slightly modified structure;

Fig. 8 is likewise a View similar to Fig. 5, but illustrating another modified structure;

Fig. 9 is a similar View, but illustrating a still further modified structure; and

Fig. 10 is a transverse section through a modified form of trigger device shown in Fig. 9.

The wrench illustrated in Figs. 1 tot, inclusive, includes a workengaging member l5, a head member 59 and a handle 22. A fiat spring bar I2 is so disposed with respect to the work-engaging member ill and the head I9 that when the handle 22 is grasped and rotated in an arc in either di rection, the pressure applied is transmitted through head I9, spring 52 and the work-enga ing member I0 to the work. As the resistance of the work causes the spring bar l2 to flex, head l9 and handle 22 will rotate relative to the workengaging member I0. The force applied to the handle 22 will continue to move the handle in an arc with the work-engaging member ID as a pivot as the work is tightened. This rotary or pivotal movement between the handle 22 and the work engaging member It is measured at a dial 18 mounted upon head I9 by a pointer I3 ecured to the work-engaging member I0.

It will be observed that in the type of wrench disclosed, applicant provides two relatively movable members which are so arranged that one of them operatively engages the work and is known as the work-engaging member. The other member is the handle or head member and the relative movement between the work-engaging member and the handle or head member is yieldably opposed by a fiat spring bar. The force applied through the wrench is determined by measuring the extent of the relative movement between these two parts. The spring bar has one end extending across the axis of rotation of the work-engaging member as indicated by dotted lines E2 in Figs. 1 and 2, this spring bar then extending rearwardly therefrom longitudinally of the handle memberv in radial relation to the axis of rotation of the work-engaging member and the other end being pivotally connected to the head. This arrangement of the parts provides a substantially continuous moment arm of substantially constant length.

It will be observed that the pointer l3 may be fixedly secured to the work-engaging member Ill so that it may appear to be an integral part thereof. It may taper however and be offset upwardly at 25 to provide sufiicient space above spring bar I2 for a trigger finger 26 adapted to be adjustably carried by pointer I3 by means of an adjusting screw 21. The tip of pointer i3 passes through an arcuate slot or ent-away portion 28 on dial l8 formed by bending part 29 in an arc to protect the pointer I3 and its tip 38. The scale reading Si is calibrated in foot pounds, or according to any desired terms,'so that when rtorque represented by a predetermined reading on dial I8 is applied through handle 22, head I9, spring bar l2 and work-engaging member Ill, the relative rotative movement of the head member I9 and handle 22 about work-engaging member IE) as a pivot through the deflection of spring bar I2 will bring pointer tip 30 to this predetermined reading and cause trigger finger 26 to engage and dicated at 39. Bar 36 is also mounted in pivotal relation upon pin 40, which lies parallel to pin 3'! but is anchored in the horizontally bifurcated end ii-of a sleeve extension 42 fixedly anchored at 43 in head member I9 and forming in fact a functionally integral part of head member I9. Bar 36 is adapted to be so disposed with respect to this bifurcated end 4I that it will normally lie across the same with its side edges disposed along or within the bifurcated openings 44 and 45. The rigid connection is normally maintained by a trip member 46 having its curved forward end 47 engaging in a correspondingly curved notch 48 (which may be pointed as will hereinafter ap- 3;

pear) in the forward end 49 of bar 36, the latter part having end edges 56 and which, as will be explained, are adapted to strike the inside surface 52 of handle 22 when this rigid connection is broken.

One possible form of mechanism for holding trip member 46 socketed in notch 48 of bar 36 to restrain the bar 36 from normally moving relative to sleeve 42 is illustrated in Figs. 4 to 6, inclusive. 54 and a coil spring 55 pressing the head 54 forwardly against trip 46 extends rearwardly of this trip 46, the head 54 and spring 55 lying in a smaller sleeve 56 slidably disposed in sleeve extension 42. 5? while trip 46 lies in the forward end of this chamber with the head 54 of rod 53 pressing thereagainst and tending to expel the trip outwardly, this action being restrained by the notch 48 during the time the rigid connection is main-- tained, as shown in Fig. 5, or by a portion of outer face 49 of bar 36, when the rigid connection is broken a shown in Fig. 6. When the rigid connectioi is broken, a portion of the outer face 49 will push the trip 46 inwardly against the tension of spring 55, the latter being compressed as shown in Fig. 6. This portion of outer face 4 9 of bar 36 will also slidably force sleeve 56 inwardly in sleeve extension 42 to compress a spring 59 of larger diameter lying between sleeve 56 and a fixed tubular member 66 anchored in sleeve extension 42 and extended in head member I6.

Trigger may in one possible embodiment of the invention comprise a pivotally mounted cam member 62 lying in a slot 63 disposed centrally in a eylindricalhousing 64 which is held in an open- A spring ressed rod 53 with a head Spring is confined in a chamber and into which the plate 66 projects for engage-' ing 65 formed in head member l6 by tubular member 66 lying in a cutaway portion 6i as shown in Figs. 4 and 6. Slot 63 may extend a substantial distance downwardly in housing .64, as shown in Figs. 3 and 4, so that an apertured shuttle plate may be disposed for slidable movement below trigger cam member 62. This cam member 62 is adapted to be pivotally carried on a pin 6? driven transversely through housing 64. A flat cam face 68 on cam member 62 functions to bear against the upper face of shuttle plate 56, which is adapted normally to be pressed upwardly against this cam face 68 by a coil spring 69 disposed in a lower chamber ID in housing 64 ment by the coil spring 69.

It will be observed in Figs. 3 and 4 that the tip of rod 53 normally lies in an aperture II, in plate 66.. When thetrigger 35, is engaged by finger 26 and its cam member is caused to. rotate about pin 61, cam face 68 will depress plate 66 and bring aperture II into alignment with an opening I2 in housing 64. When this occurs, the tip of rod 53 will be forced forwardly to move into opening l2 by the force being applied at the handle, which force is of course transmitted by these parts to the head member I9. .Thus the rigid connection is broken and force being applied at handle 22 is utilized to swing bar 36 in a hammer blow action against the inside surface 52 of the handle. It will be apparent that this hammer blow may be equal to the force imparted to the handle by the operator and that its striking effect will be of a magnitude to be definitely imparted by a jarring action to the operator and leave no doubt about the predetermined torque represented by the setting of trigger finger 26 being imparted to the work by the work-engaging member I6. Thus, with the impact action equal to the force imparted to the handle by the op,- erator, the rigid connection between the handle and the head member is temporarily broken, but will b quickly restored by the tendency of the parts automatically to reset when the force imparted to the handle is released. i

When the handle 22 is grasped and rotated in either direction, the pressure applied will be transmitted throughth'e head I9, spring bar I2 and the work-engaging member It to the work. As the resistance of the work causes the spring I2 to flex, relative rock movement takes place between the head I6 and work-engaging member I0 and the amount of the force applied may be measured by the extent of this rock movement through the pointer I3 and gauge dial I8. If the handle 22. is to be rotated clockwise as viewed in Fig. 1, trigger finger 26 is set to engage the trigger 35 when a predetermined torque is applied to the work as determined by this relative rock movement between head I9 and workengaging member I6. This will effect a release of part 36 so that it will swing to the position shown in Fig. 6, to-wit: with corner 56 striking handle wall 52 and with a portion of face 49 forcing trip 46 inwardly to compress springs 54 and 59 and hold rod 53 in opening 12 in housing 64.

The feature of automatic resettingof the parts to restore the rigid connection is obviously ac+ complished once the force applied to the handle is discontinued. The spring bar I2 will then straighten to return trigger finger 26 to a posia tion away from the trigger 35, and the pivotal action of handle 22 about pin 31 together with the pivotal mounting of bar 36 on pin 46 will cause this handle to straighten, this bar 36 also straightening by reason of its double pivotal mounting at 31 and 46, so that the portion of face 49 of bar 36 will no longer abut against trip 46. Spring 55 will then move rod 53 to withdraw its tip from opening 72 in housing 64, whereupon spring69 in chamber 65 in head I9 will lift shuttle plate 66 to the position shown inFig. 4 and the trigger cam plate 62 will assume its normal position shown in Fig. 3. Trip 46 will be forced into notch 46 in bar 36 and the forward face I5 of sleeve 56 will be brought and held against face 49 of bar 36. Thus the rigid connection is effectively restored by a tendency of the parts to be automatically resettable.

The parts comprising the normally rigid connection includin bar 36 transmitting the force imparted to handle 22 to head l9, bar I2 and Work-engaging member III to the work may be assembled in any suitable way. However, as illustrated in the drawings, pin 46 is used to hold these parts in position, thereby simplifying the assembly of the parts and making replacement of a, part a simple matter. It will be observed that pin 46 is headed at one end and i provided with a groove at the other end to receive a spring ring 46' holding pin 46 in assembled position. The removal of ring 46' and pin 46 disconnects handle 22 and bar 36 from sleeve extension 42. Trip 68 and associate parts like rod 53, springs 55 and 59, sleeve 56, tubular member 66 will be free for removal, while housing 64, shuttle plate 66 and its spring 69 may be dropped out of chamber 65. It will be apparent that the assembly is as simple and will involve little labor. It is not tedious and the parts are designed to drop readily into their proper relative positions to be held assembled by the locking of pin 46 in position as illustrated in Fig. 4.

V will be apparent any looseness of the parts due to wear will not affect the making of the norfinger 26. This movement of plate 66 will bring the tip of rod 96 into registration with opening I2 to cause trip 88'to be forced out of notch 8'1 and arm 8I allowed to utilize the force being iniparted to handle 86 to swing into a position about pins 82 and 83 to produce a hammer blow by striking against handle 86.

mally rigid connection for transmitting the force imparted at the handle, or will not affect the operation of the spring bar in flexing, and. the operation of the pointer and dial t indicate the extent of this flexing which acts to measure the torque applied at the work-engaging member to the work. Bar 36 will be tripped in the same way and the hammer blow effected to indicate or signal the application of a predetermined torque at the work.

Different forms of structure may be provided to accomplish the results of the invention disclosed. In Fig. '7, handle 86 is similarly mounted upon a bar 8| by a pin 82 fixedly attached to handle 86. Bar 8I is also pivotally carried upon a pin 83 secured in bifurcated sleeve 84, bar 8| lying crosswise of the bifurcated portion so that it moves outwardly of either opening 85 or 86 when swung about pins 82 and 83. Bar BI is designed in the same manner and is provided with an arcuate notch 87 to receive a trip 88 slidably carried within a sleeve 89 of smaller diameter disposed within the bifurcated sleeve 84. [A rod 96 extends outwardly of sleeve 89 and is provided with a head 9| lying therein and abutting against trip 88, there being a spring 92 urging this head 9| against the trip 88 to hold it against bar 8| to maintain the rigid connection transmitting the-force imparted to the handle. Another coil spring 93 is disposed within sleeve 86 to urge the smaller sleeve 89 outwardly so that the end face 94 of the latter will be held against the end face 95 of bar 8I when maintaining the rigid connection. A fixed tubular member 96 is likewise seated in the inner end of sleeve 84 and also partly, in head member 91. trigger device. cooperating with the end of rod The parts of the The force to keep trip 88 in notch 81 of bar 8| in this embodiment will not be as great as in the previous form, and consequently, spring 92 need not be as large as spring 54. Trip 88 is provided in two parts 98 and 89 having sloping cooperating faces adapted to produce frictional resistance resisting movement. This tends to keep these parts in position to maintain the rigid connection, but this connection will be readily broken as in the former case when plate 66 moves to bring the tip of rod 96 into opening 12.

In the embodiment disclosed in Fig. 8, the handle I62 is likewise mounted upon a bar I63 by a pin I fixed in handle I62. Bar I63 is also pivotally carried upon a pin 65 secured in the bifurcated sleeve I66. Bar I63 is provide d in this instance with a V-opening (referred to hereinabove) I68 in its front face till adapted to receive a V-tip I69 at the end of a trip H6 arranged in this instance toinclude a chamber II I in which the head II! of rod H8 is disposed. A coil spring Ii9 encircles the rod H8 and is also disposed in chamber III to urge rod H8 forwardly in constant contact with trip H8 while spring I26 in sleeve I66 urges trip H6 forwardly so as to hold V-tip I69 innotch I68. Thus the smaller sleeve housing the trips in the other embodiment is made a part of the trip in this form and the chamber III is formed directly therein so that the spring H9 and the head II! of the rod IIS will lie therein. A plate IZI may be placed upon rod H8 at head III for spring H9 to press thereagainst, while at the opposite end 'over as at I23 to hold the plate I22 in position.

In all other respects, the parts are the same as .in the previous forms andfunction in a like manner.

, In Fig. 9 there is illustrated ,an embodiment employing another form of the invention. Handle I25 is mounted upon a bar I26 by a pin I12? fixed in handle I25. Bar I26 is also pivotally carried upon a pin I26 secured in bifurcated sleeve I29. An arcuate notch I36 in bar I26 is adapted to receive an arcuate knob E3! on the outer face I32 of trip I33 which is slidably movable in sleeve I29. At the rear end of sleeve E29, a smaller sleeve I38 is anchored, a portion extending in head member I35 if so desired. Withbears thereagainst.

in sleeve i556 is disposed concentrically arranged springs I35 and I36. Spring I35 is arranged to encircle a rod I3! adapted to be anchored in a member I38 having a tapered face I38 at its outer end adapted to bear against ball bearings i ls riding against the inner face 'of trip I33. Sleeve E33 is likewise provided with a tapered face I II which also has the bearings M6 riding thereagainst. A sleeve M2 is carried upon the forward end of member i38 -and the spring I36 Thus the bearings N2 are forced forwardly and toward the center against surface I39 of member I38, and thus the force to keep trip I33 against bar' I26 to maintain the normally rigid connection need not be as great.

Another form of trigger device that may be used instead of that illustrated in Figs. 1 to 8, inclusive, is shown in Fig. 10. Instead of employing vertically slidable shuttle plate 66, a rotatable housing 145 is disposed in head member I35 and i provided with two openings I46 and M! (Fig. 9) adapted to be brought alternately into registration with red i31. A trigger I48 projects from housing M5 to be engaged by trigger arm 26 and moved in either direction depending upon the direction of rotation of handle I25 when grasped to apply torque to the work. Housing M5 is provided with a chamber I49 for receiving a torsion spring I55 anchored at one end by screw l5! and at the other end by screw I52. Obviously, housing M5 will be returned to its normal position with its trigger I48 lying longitudinally of the wrench when the trigger I 48 is disengaged by trigger finger 25 and the force applied to the handle is released. When the force is released at the handle, it is apparent that the tip of the rod of this mechanism is Withdrawn from either opening MB or Ml and the housing M5 is then permittedto rotate to normal position.

Attention is directed to the fact that in this art the entire portion of the device from the end of the spring [2 to the end of the handle 22, which includes head l9 and sleeve extension 42, as shown in Figs. 1 to 6, inclusive, is often termed the handle member and the part which I have herein termed handle 22 is often called a grip member. On the other hand, this portion has also been broadly called a head member, in which event handle 22 may or may not be included as a part thereof. It will be understood, therefore, that the term force applying member as used herein is intended to include the handle, if it is provided, and all other parts going to make up the same, and that the hammer blow may be directed against any part thereof.

From the foregoing description, it will be apparent that an exceedingly novel structure, in a force transmitting device, is disclosed and that the mechanism forming a normal rigid force transmitting connection adapted to release itself and produce a hammer blow, by the force being transmitted, by a trigger device actuable to indicate the application of a predetermined torque at the work, or indicate the extent of the application of this force being transmitted, may be made and disposed of as a unit independently of the force transmitting device without departing from the scope of the invention. Although, in most force transmitting devices incorporating the invention, a torque measuring device may be employed, it will be understood that the invention has use in force transmitting devices not having a torque measuring device.

I believe that I am the first to provide a force transmitting connection that normally remains rigid to transmit force but which is adapted to be released to produce a hammer blow to the mechanism no matter where the hammer blow may be applied. This hammer blow is of a magnitude that leaves no uncertainty about its application to the mechanism When it is applied, and hence, it serves as a Very effective'signal, either audible or in a tactile sense. The parts are simple, easy to assemble and permit incorporation in any force transmitting device at a reasonable cost. The jar produced at the handle, if incorporated in a torque measuring wrench as disclosed herein, tends to facilitate the use of the wrench in that it adds to the speed at which the attendant handles the wrench and assures more accurate application of a predetermined torque at the work.

As a further application of the invention, its use to indicate a limited movement, straight or otherwise, of a device, such for example as a slide on a milling machine, or a shuttle on a grinder, will be apparent from the foregoing description. A suitably spaced element or the like may be used to effect a tripping action to produce the hammer blow against the structure to indicate a predetermined travel to the operator gripping the handle, so that it will act as a warning to cause him to bring the operation to a stop when a certain point in the movement is reached. In this connection, and for many similar uses, the portion of the structure disclosed herein beginning at the head l9 and extending rearwardly to and includin the handle 22 may be employed, the tripping action occurring when a properly posi-. tioned trip element engages member 35. It will be apparent that such uses and modifications may be made without departing from the invention,

Without further elaboration, the foregoing will so fully explain the gist of my invention that others may, by applying current knowledge, read-. ily adapt the same for use under varying conditions of service, without eliminating certain features, which may properly be said to constitute the essential items of novelty involved, which items are intended to be defined and secured to me by the following claims.

Iclaim:

l. A tripping mechanism for indicating the application of a predetermined force adapted for use with a force transmitting mechanism which, includes a handle member and a yieldably connected force applying member, said tripping mechanism comprising a normally rigid connection through'which the force imparted to said handle member is transmitted to said force applying member, a releasable member forming a part of said means adapted to break said normally rigid connection and deliver a hammer blow to jar said handle member, said member comprising a bar pivotally mounted upon said handle and upon said force applying member, there being means for restraining said bar to prevent said bar from swinging about its said pivotal mountings. V

2. A force transmitting mechanism comprising a force applying member, a work-engaging member, a torque measuring device interposed between said force applying member and said work-engaging member, means for momentarily releasing the force of the load being applied by said force applying member and for utilizing the force to create a hammer blow to jar said force applying member, a trigger device for operating said 'releasing means, and means actuable through movement of said torque measuring device to actuate said trigger device.

3. A force transmitting mechanism comprising a force applying member having a grip portion, a work-engaging member, a torque measuring device interposed between said force applying memher and said work-engaging member, means for momentarily releasing the force of the load being applied at said grip portion and for utilizing the force to create a hammer blow to jar said grip portion, a trigger device carried by said force applying member for operating said releasing means, and means actuable through movement of said torque measuring device to actuate said trigger device. 1

4. A force transmitting mechanism comprising a force applying member including a handle member, a work engaging member connected to said force applying member, a normally rigid connection between said handle member and said force applying member, said connection includinga releasable member adapted to be actuated to break said connection upon the application of a predeterminedtorque at said work-engaging member to effect a hammer blow against said handle member, trigger means for said releasing member, and a part indicating the application of a predetermined torque at said work-engaging member for tripping said trigger means.

7 5. A force transmitting mechanism comprising a manually operable force applying member, a work engaging member connected to said manually operable force applying member, there being an overload release connection between said members including a part through which force imparted to said manually operable force applying member is transmitted to said work-engaging member, said part forming a part of a rigid connection for transmitting the force and adapted upon release to strike said force applying member, and actuating means for causing said part to break said rigid connection and deliver. a hammer blow to jar said manually operable force applying member there being means controlled by the torque at said work-engaging member for operating said actuating means, said actuating means including provisions for, automatically resetting said part to restore said rigid connection when the force applied to said manually operable force applying member is disconbreaking said connection, and a trigger device controlling said trip whereby said trip releases said part to break said connection and cause said part to deliver a hammer blow to jar said manually operable force applying member upon the application of a predetermined torque at said work-engaging member by the force imparted to said manually operable force applying member.

'7. A force transmitting mechanism comprising a manually operable force applying member, a Work-engaging member connected to said manually operable force applying member, there being included a part through which the force imparted'to said manually operable force applying member is transmitted to said work-engaging member, said part being pivotally related to said manually operable force applying member but normally forming a part of a rigid connection for'transmitting the force, a trip for restraining said part against pivotal movement, spring means for urging said trip against said part, and a movable member for releasing said spring means member being operable upon the application of a predetermined torque at said work-engaging member by the force imparted to said manually operable force applying member.

-8. A torque measuring wrench comprising a head member, a work-engaging member pivotally supported adjacent one end of said head member, a spring yieldably opposing relative rock move ment of said work-engaging member and said and said trip whereby to free said part and effect a hammer blow thereby to jar said manually operable force applying member, said movable head member, means for indicating the force applied to the work by registering the extent of the relative rock movement of said work-engaging and said head members, a handle member, a connection between said handle member and said head member for transmitting the force applied at the handle to the head member and transmitted through said spring and work-engaging member, said connection including rele sing means for imparting a blow to jar said handle member, said releasable means being actuable by said indicating means. a

9; A torque measuring wrench comprising a,

work-engaging member, a head member adapted for rock movement relative to said work-engaging member, a spring yieldably opposing said movement, means for indicating the force applied to the work by registering the extent of relative rock movement of said work-engaging member and said head member, a handle member pivotally mounted at one end of said head member, the pivotal mounting for said handle member including a bar pivoted upon one end of said head member and to said handle member, a trip for normally restraining said bar from moving relative to said head and handle members, a

trigger actuable by said indicating means upon the application of a predetermined torque at said work' engaging member, the movement of said trigger releasing said trip. and said bar, the

, release of said bar about its pivotal connections with said head member and said handle member creating a hammer blow to jar said handle member,

10.,A torque measuring wrench comprising a work-engaging member, a head member adapted for rock movement relative to said work-engaging member, a spring yieldably opposing said movement, means for indicating the force applied to the Work by registering the extent of relative rock movement of said work-engaging member and said head member, a handle member at one end of said head member, a connection between said handle member and said head member including a bar, means for restraining said bar from moving relative to said head member whereby said bar transmits to said head member the force applied'to said handle member, and means for releasing said restraining means to break said force transmitting connection formed by said bar and cause the bar to create a hammer blow to jar said handle member, said releasing means being actuable by said indicating means.

11. A torque measuring wrench comprising a work-engaging member, a head member adapted for rock movement relative to said work-engaging member, a spring yieldably opposing said movement, a handle member at one end of said head member, a bar forming the connection between said handle member and said head member, means for restraining said bar from moving relative to said head member whereby said bar transmits to said head member the force applied to said handle member, and meansoperated by a predetermined torque at said work-engaging member reflected by the yield of said spring for force transmitting connection formed by said bar and cause the bar to create a hammer blow to jar said handle member, said releasing means being operated by a part actuated by the relative rock movement between said work-engaging member and said head member.

12. A torque measuring wrench comprising a work-engaging member, a head member adapted for rock movement relative to said work-engaging member, a spring bar yieldably opposing said movement, a handle member at one end of said head member, means forming a connection between said handle member and said head member, means for restraining said connecting means from movement relative to said head member whereby said connecting means transmits to said head member the force applied to said handle member, and means operated by a predetermined torque at said work-engaging member reflected by the yield of said spring for releasing said restraining means to break said force transmitting.

connection and cause said connecting means to effect a hammer blow to jar said handle member, said releasing means being operated by a part actuated by the relative rock movement between said work-engaging member and said head member.

13. A torque measuring wrench comprising a work-engaging member, a head member mounted for rock movement about said work-engaging member by means of a spring bar disposed between said head member and said work-engaging member and yieldably opposing relative rock movement between said members, a handle member carried by said head member, a normally rigid connection for transmitting to said head member the force applied to said handle member, and means including a part operable by the flexing of said spring bar between said head member and said work-engaging member for breaking said connection upon the application of a predetermined torque at said work-engaging member, said connection when broken utilizing the force of the load being applied to create a hammer blow to jar said handle member, said means including provisions for automatically resetting the same to restore said rigid connection by the release of the force applied from said handle member.

14-. A torque measuring Wrench comprising a work-engaging member, a head member, a spring bar disposed between said head member and said work-engaging member for yieldably opposing relative rock movement of said head member and said work-engaging member, means for indicating the force applied to the work by registering the extent of relative rock movement of said work-engaging member and said head member, a handle member at one end of said head member, a mounting for said handle member, said mounting including a bar normally forming a rigid connection between said head member and said handle member, a spring pressed trip for restraining movement of said bar relative to said head member, a projection on said trip, a slidable plate, said plate having an aperture therein adapted for registration and the reception of said projection, and a pivotally mounted trigger adapted to be actuated by said indicating means to force said slidable plate into position to cause said projection to register with and be received in said aperture to break said rigid connection formed by said bar.

15. A torque measuring wrench comprising a work-engaging member, a head member, a spring bar disposed between said head member and saidwork-engaging member for yieldably opposing relative rock movement of said head member and said work-engaging member, means for indicating the force applied to the work for registering the extent of relative rock movement of said work-engaging member and said head member,

. a handle member atone end of said head member, a mounting for said handle member, said mounting including a member normally forming a rigid connection between said head member and said handle member, a spring pressed trip for restraining movement of said member relative to said head member, a projection on said trip. a spring pressed sleeve housing said trip, said projection extending throughsaid sleeve, a movable plate having an aperture therein adapted for registration and the reception of said projection, and a pivotally mounted trigger adapted to be actuated by said indicating means to force said movable plate into position to cause said projection to register with and be received in said' aperture to break said rigid connectionformed by said member.

16. A t'orque measuring wrench comprising a work-engaging member, a head member: a spring bar disposed between said head member and said. work-engaging member for yieldably opposing relative rock movement of said head member and said work-engaging member, means for indicat ing the force applied to the work for registering the extent of relative rock movement of said work-engaging member and, said head member, ahandle member at one end of said head member, a mounting for saidhandle member, said, mounting including a member normally'forming a rigid connection between said head-member and said handlemember, a spring pressed trip 40 for restraining movement of said member relative to said head member, a projection on said trip, a movable plate having an aperture there- 'in adapted for registration and'the reception of said projection, and a pivotally mounted trigger adapted to be actuated by said indicating means to force said movable plate into position to cause said projection to register with and be received in said aperture to break said rigid connection formed by said member.

oil

17. A torque measuring wrench comprising a work-engaging member, a head member, a spring bar disposed between said head member and said work-engaging member for yieldably opposing relative rock movement of said'hea-d member and said work-engaging member, means; for indicating the force applied to the work for registering the extent of relative rock movement of said work-engaging member and said head member,- a handle member at one end of said head member, a mounting for said handle member, said mounting including a member normally forming a, rigid connection between said head member and said handle member, a spring pressed trip for restraining movement of said member relative to said head member, a projection on said trip, a rotatable body disposed in said head member, said rotatable body having an aperture therein adapted for the registration and the reception ing a work-engaging member, a manually operable force applying member connected thereto through the intermediary of an overload release mechanism, a torque measuring device operatively disposed relative to said work-engaging mam ber and said manually operable force applying member, and means actuable through movement of apart of said torque measuring device for momentarily releasing said mechanism and utilizing the applied force to create a hammer blow againsta part of said force transmitting mecha said manually operable member upon being released, means for indicatingthe force applied to the work by said work-engaging member, and means for tripping said overload release by move-v ment of a part of said indicating means,

20. A force transmitting mechanism compris ing a manually operable force applying' member, a work-engaging member connected to said force applying member, an over-load release through which force imparted to said manually operable member is transmitted to said work-engaging member, said overload release including a releasablemember adapted to effect a hammer blow to jar said manually operable force applying member, means for indicating the torque ap plied at said work-engaging member by the force transmitted through said over-load release, and a trip actuable at a predetermined setting for re-' leasing said releasing member, said trip being actuable through the movement of said torque indicating means.

21. A torque measuring wrench comprising a work-engaging member, a head member mounted for rock movement about said work-engaging member by means of a spring bar disposed be- I tween said head member and said work-engaging member and yieldably opposing relative rock movement between said members, a handle member carried by said head member, a normally rigid connection for transmitting to said head member the force applied to said handle member, and means actuable through the flexing movement of said spring bar for breaking said connection upon the application of a predetermined torque at said work-engaging member, said connection including means to deliver a hammer blow when saidconnection is broken, said connection when broken utilizing the force of the .load bein applied to create said hammer blow necting mechanism and one of said parts of said force transmitting device, and a tripping device for said blocking member adapted to cause said blocking member to free said movable member for movement in the direction or" the force, the movement of said movable member releasing said releasable member to cause said releasing member to deliver a hammer blow against one of said parts of said force transmitting device.

23. Connecting mechanism for use between parts of a force transmitting device comprising means for connecting said mechanism to each part and to provide a normally rigid connection between these parts to transmit force from one part to the other, said mechanism including a member adapted to be urged by the force transmitted to move in the direction of the force, a blocking member to prevent such movement of said movable member, a releasable member to provide a force transmitting connection between said movable member and one of said parts of said force transmitting device, and a tripping de vice for said blocking member adapted to cause said blocking member to free said movable member for movement in the direction of the force, the movement of said movable member releasing said releasable member and delivering a hammer blow at the time of said release against one of said parts of said force transmitting device.

24. Connecting mechanism for use between parts of a force transmitting device comprising means for connecting said mechanism to each part to effect a normally rigid connection between these parts whereby to transmit force from one part to the other part, said mechanism including a member movable forwardly in the direction of force transmitted, a blocking member preventing such forward movement of said member, a trip to actuate said blocking member to allow said movable member to move forwardly, and a releasable member adapted to be released by the forward movement of said movable member causing a hammer blow at the time of said release against one of the parts of said force transmitting device.

25. A force transmitting mechanism comprising a, force applying member including a handle member, a, work-engaging member, a torque measuring device operatively disposed relative to said force applying member and said work-engaging member, a normally rigid connection between said handle and said force applying member by means of which theforce imparted to said handle member is transmitted to said force applying member, a releasable member forming a part of said normally rigid connection and through which the force imparted to said handle member is transmitted to said force applying member adapted to break said normally rigid connection and deliver a hammer blow to jar said handle member, means for actuating said releasable member, and a part actuable by relative movement between said work-engaging member and said force applying member for operating 7 said actuating means.

mitted to move in the direction of the force, a

26. A torque measuring wrench comprising a head member, a work-engaging member pivoted adjacent one end of said head member, a spring bar disposed between said head member and said work-engaging member and yieldably opposing relative rock movement between said members, a handle member at the opposite end of said head member, a normally rigid connection between said handle member and said head member 2,885,591 9 adapted to comprise a force transmitting conand effect thereby a hammer blow directly against nection, said connection including means to desaid handle member, said releasing means being liver a hammer blow against said handle memactuated by a part actuated by the relative rock her, and means for releasing said normally rigid movement between said Work-engaging member connection upon the application of a predeter- 5 and said head member.

mined torque at said work-engaging member PAUL A. STURTEVANT. whereby to break said normally rigid connection 

